Evans' Syndrome in Adults: An Observational Multicentre Study

Abstract Evans syndrome (ES) is a rare condition, defined as the presence of 2 autoimmune cytopenias, most frequently autoimmune hemolytic anemia and immune thrombocytopenia (ITP) and rarely autoimmune neutropenia. ES can be classified as primary or secondary to various conditions, including lymphoproliferative disorders, other systemic autoimmune diseases, and primary immunodeficiencies, particularly in children. In adult ES, little is known about clinical features, disease associations, and outcomes. In this retrospective international study, we analyzed 116 adult patients followed at 13 European tertiary centers, focusing on treatment requirements, occurrence of complications, and death. ES was secondary to or associated with underlying conditions in 24 cases (21%), mainly other autoimmune diseases and hematologic neoplasms. Bleeding occurred in 42% of patients, mainly low grade and at ITP onset. Almost all patients received first-line treatment (steroids with or without intravenous immunoglobulin), and 23% needed early additional therapy for primary refractoriness. Additional therapy lines included rituximab, splenectomy, immunosuppressants, thrombopoietin receptor agonists, and others, with response rates >80%. However, a remarkable number of relapses occurred, requiring ≥3 therapy lines in 54% of cases. Infections and thrombotic complications occurred in 33% and 21% of patients, respectively, mainly grade ≥3, and correlated with the number of therapy lines. In addition to age, other factors negatively affecting survival were severe anemia at onset and occurrence of relapse, infection, and thrombosis. These data show that adult ES is often severe and marked by a relapsing clinical course and potentially fatal complications, pinpointing the need for high clinical awareness, prompt therapy, and anti-infectious/anti-thrombotic prophylaxis.